This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. During ascending infection, the choriodecidua is the first-line barrier in contact with pathogens that can cross the membranes and infect the amnion and amniotic fluid. Virulent bacteria such as group B Streptococci or E. coli have been shown in vitro to adhere, invade and transcytose through intact chorioamniotic membranes. However, localized inflammatory response in vivo is likely to weaken the structural integrity of the chorioamnion and to allow a less virulent microorganism to also breech this barrier. For instance, mucosal surface pathogens such as Mycoplasma hominis or Ureaplasma species have been reported to infect the amniotic cavity quite early in gestation without rupture of the fetal membranes. Despite this, there is no direct experimental evidence demonstrating that U. parvum can breech the intact chorioamniotic membranes and gain entry into the amniotic cavity. This series of in vitro studies will extend and complement the in vivo data obtained from our experimental choriodecidual model. Transmigration of U. parvum will be determined under a series of experimental conditions (choriodecidual exposure vs. amniotic exposure). Differential production rates of specific biomarkers by component tissue layers will illuminate the tissue source of specific biomarker profiles observed in the amniotic fluid and cervical vaginal fluid (CVF) during intra-uterine infection (choriodecidual vs. intra-amniotic infection). Moreover, these studies will provide important information on the contribution of the amnion or choriodecidua to the inflammatory response following U. parvum exposure in utero.